brakes AUDI A8 2014 Owner's Manual

242 Checking and filling
-The auxiliary e lectric fan is temperature
controlled and can switch on suddenly
even when the engine is not runn ing.
- The auxiliary radiator fan switches on au­
tomatically when the engine coolant
reaches a certain temperature and will
continue to run until the coolant temper­
ature drops .
Brake fluid
Checking brake fluid level
The brake fluid level can be checked with a
quick glance.
Fig . 205 E ng ine co mpartment: cove r on the brake fluid
r eservo ir
Before you check anything in the engine com­
partment,
always read and heed all WARN­
INGS 9 &_ in Working in the engine compart­
m ent on page 231.
.. Read the brake fluid level from the brake
fluid reservoir
9 fig . 205, q page 233. The
brake fluid leve l must be between the "MIN"
and "MAX" markings.
The location of the brake fl uid reservoir can be
seen in the engine compartment illustrat ion
9 page233.
The fluid level may drop slightly after some
time due to the automatic adjustment of the
brake pads. This is not cause for alarm.
If the brake fluid level falls
considerably be­
low the "MIN" mark, the brake warning/ind i­
cator light
1111 (U.S. models)/ . (Canadian
models) will come on
q page 14. Do not con­
tinue to operate the vehicle . T he complete
brake system should be thoroughly checked by an authorized Audi dealer or other quali­
fied fac ility and the cause corrected.
If th e
brake flu id level is too low, the brake wa rning/
indicator light will illuminate. Contact an au­
thorized Audi dealer
immediately.
Changing brake fluid
Have the brake fluid changed by on experi­
enced technician.
Brake fluid absorbs moisture from the air. If
the water content in the brake fluid is too
high, corrosion in the brake system may result
a fter a period of time. The boiling point of the
brake fluid will also decrease considerably and
decrease braking performance .
Therefore, the brake fluid must be changed
every two years. Always use new brake flu id
which conforms to Federal Motor Veh icle
Standard "FMVSS 116 DOT 4" .
The brake fluid reservoir can be difficu lt to
reach, therefore, we recommend that you
have the brake fluid changed by your author ­
ized
Audi dealer . Your dealer has the correct
tools, the right brake fluid and the know-how
to do this for you .
.&, WARNING
-Brake fluid is poisonous. It must be stor­
ed only in the closed origina l container
out of the reach of children!
- Brake failure can result from old or inap­
propriate brake fluid. Observe these pre­
cautions:
- Use only brake fluid that meets SAE
spec ification
J 1703 and conforms to
Federa l Motor Vehicle Standard 116.
Always check with your authorized Aud i
dealer to make sure you are using the
correct brake fluid. The correct type of
brake fluid is also indicated on the
brake fluid reservoir .
- The brake fluid must be new. Heavy use
of the brakes can cause a vapor lock if
the brake fluid is Left in the system too
lllJ.

long. This can seriously affect the effi­
ciency of the brakes as well as yo ur
safety. This could result in an acc ident.
0 Note
Brake f luid will damage the paint of your
vehicle.
@ For the sake of the environment
Because of the problem of proper d isposa l
of brake fl uid as we ll as the special tools
req uired and the necessa ry expert ise, we
recommend that you have the brake fluid
changed by your author ized Audi dealer.
Battery
General information
Under normal operating conditions, the bat ­
tery in your A udi does not need any mainte ­
nance . With
high outside temperatures or
long dai ly dr ives we recommend that you have
the electro lyte level checked by a service fa­
cility. T he electrolyte level shou ld also be
checked each time the battery is charged
-:;, page 245.
Have the battery checked when you take your
ve hicle in for service. You are well adv ised to
replace a battery that is older than 5 years.
W ith certa in types o f airbag deployment, the
battery is d isconnected from the vehicle elec­
tr ica l system for safety reasons¢
& in Re­
pair, care and disposal of the airbags on
page 167.
Disconnect ing the battery terminals
Some vehicle functions (power w indow regu­
lators, for example) are lost if the battery ter­
minals a re d isconnected. These functions have
to be relearned after the battery terminals a re
connected again . To prevent this, the battery
should only be d isconnected from the vehicle
e lec trica l system whe n absolu tely ne cessa ry
f or repairs.
Checkin g and fillin g 243
Vehicles not driven for long periods
If you do no t drive your vehicle over a period
of seve ra l days o r weeks, e lectr ica l compo ­
nents are g radually cut back or switched off .
This reduces energy consumption and main­
ta ins starting capability over a longer period
¢
page 204. Some of the convenience func­
tions may not operate, such as the inter ior
l igh ts or the power seat adjus tment. The con­
venience functions will be ava ilab le aga in
whe n you swi tch on the ignition and sta rt the
engine.
Winter operation
During the winte r months, battery capacity
tends to dec rease as temperatures drop. This
i s because more power is a lso consumed wh ile
s ta rt ing, and the headlight s, rea r window de­
fogger, e tc., are used more ofte n.
Avoid unnecessary powe r consumpt ion, par­
ticu larly in city traffic o r when traveling only
sho rt distances. Let yo ur au thoriz ed Aud i
de aler check the cap acity of the vehicle b at­
tery before winter sets in~ page 245. A well
charged bat tery will not on ly prevent starting
problems w hen the weather is cold, but w ill
a lso last longer.
{!) Tips
If yo ur vehicle is left s tandin g for seve ral
weeks at extreme ly low tem peratures, the
vehicle battery sho uld be removed and
stored w here it w ill not freeze . T his will
prevent it from be ing damaged and having
to be replaced.
Working on the battery
Be especially careful when working on or near
the battery.
The battery is located in the luggage compart ­
ment under the floor. Before you check any­
th ing in the luggage compartment,
read and
heed all WARNINGS
¢ .&_ .
Always heed the safety warnings , when work­
ing on the vehicle battery or the vehicle e lec­
trical system to prevent injury. •
•

-Never mount used tires on yo ur vehicle if
yo u are not sure of their "previous histo­
ry." Old used tires may have been dam­
aged even though the damage cannot be
seen that can lead to sudden tire failure
and loss of vehicle control.
- If you notice unusual vibration or if the
vehicle pulls to one side when d riving, al­
ways stop as soon as it is safe to do so
and check the wheels and tires for dam­
age .
(D Note
Please note that summe r and wi nte r tires
are designed for the cond itions that are
Glossary of tire and loading terminology
Accessory weight means the comb ined weight (in excess of
those sta ndard items which may be rep laced)
of au toma tic transmission, power steer ing ,
power brakes, power windows, power seats,
radio, and heater, to the extent that these
items are availab le as factory-installed equip­
ment (whether installed or not) .
Aspect ratio
means the rat io o f the height to the w idth of
the tire in percent . Numbers of 55 or lower in ­
dicate a low sidewall for improved steering re­
sponse and better overa ll handling on dry
pavement .
Bead
means the part of the t ire t hat is made o f
steel wires, wrapped or reinforced by ply cords
and that is shaped to fit the r im.
Bead separation
means a b reakdown of the bond between
components in the bead .
Cord means the strands forming the plies in the
tire.
Tire s an d wheel s 249
typica l in those seasons . Aud i recommends
using winter tires during the winter
months . Low temperatures signif icant ly
dec rease the e lasticity of summer t ires,
which affects tract ion and brak ing ability.
If summer t ires are used i n very co ld tem ­
peratures, cracks ca n form o n the tread
bars , res ulting in perma nen t tire damage
that can cause loud driving noise and un­
bala nced ti re s. Audi i s not respon sible for
th is type of damage .
Cold tire inflation pressure
means the t ire p ress ure recommended by t he
vehicle manufacture r fo r a tire o f a des ignated
s ize t hat has not bee n driven for more than a
coup le o f miles (k ilometers) at low speeds in
the three hour period before the tire press ure
is m easured or adjusted.
Curb weight
me ans the we ight of a motor ve hicle with
st andard equipmen t incl ud ing the max imum
capacity of fuel, oi l, and coolant, air condi ­
tioning and additional weig ht of optiona l
equipment.
Extra load tire
means a t ire design to oper ate a t higher load s
and at higher inflation pressures than the cor­
responding standa rd tire . Extra load tires may
be identified as "XL", "x l", "EXTRA LOAD", o r
"RF" on the sidewal l.
Gross Axle Weight Rating ("GAWR")
me ans the load-ca rry ing capac ity of a single
axle system , measured at the tire -ground in­
te rfaces.
Gross Vehicle Weight Rating ( "GVWR ")
mea ns the maximum total loaded we ight of
the ve hicl e. .,..
•
•

250 Tires and wheels
Groove
means the space between two adjacent tread
ribs .
Load rating (code)
means the maximum load that a tire is rated
to carry for a given inflation pressure. You
may not find this informat ion on all tires be­
cause it is not req uired by law.
Maximum load rating
means the load rating for a t ire at the max i­
mum permissible inflation pressure for that
tire.
Maximum loaded vehicle weight
means the sum of:
(a) Curb weight
(b) Accessory weight
(c) Vehicle capacity we ight, and
(d) Production options weight
Maximum (permissible) inflation pressure
means the maximum cold inflation pressure
to which a tire may be inflated. Also called
"maximum inflation pressure ."
Normal occupant weight
means 150 lbs. (68 kilograms) times the
number of occupants seated in the vehicle up
to the total seating capacity of your vehicle .
Occupant distribution
means distribution of occupants in a vehicle.
Outer diameter
means the overa ll diameter of an inflated new
tire.
Overall width
means the linear distance between the exteri­
ors of the sidewalls of an inflated tire, includ­
ing elevations due to labeling, decorations, or
protective bands o r ribs .
Ply
means a layer of rubber-coated parallel cords.
Production options weight
means the combined weight of those insta lled
regular production options weighing over 5
lbs. (2.3 kg) in excess of those standard items
which they replace, not previously considered
in curb weight or accessory we ight, including
heavy duty brakes, ride levelers, roof rack,
heavy duty battery, and special tr im .
Radial ply tire
means a pneumat ic tire in which the ply cords
that extend to the beads are laid at substan­
t ia lly 90 degrees to the center line of the
tread .
Recommended inflation pressure
see<=> page 249, Cold tire inflation pressure.
Reinforced tire
means a t ire design to operate at higher loads
and at h igher inflation pressures than the cor­
responding standa rd tire. Reinforced tires
may be identified as "XL" "xl" "EXTRA LOAD"
' ' '
or "RF" on the sidewa ll.
Rim
means a metal support for a tire or a tire and
tube assembly upon which the tire beads are
seated.
Rim diameter
means nom inal diameter of the bead seat. If
you change your wheel s ize, you will have to
purchase new tires to match the new rim di­
ameter.
Rim size designation
means r im diameter and width .
Rim width
means nominal distance between rim flanges.
Sidewall
means that portion of a tire between the
t read and bead.

254 Tire s and wheel s
vehicle with diffe rent rims/ti res or you bought
the vehicle as a previously owned vehicle.
Remembe r, your safety and that of your pas­
sengers also depends on mak ing sure that
l oad limits are not exceeded . Vehicle load in­
cludes everybody and everything in and on the
ve hicle . These load limits are technically refer­
red to as the vehicle's Gross Vehicle We ight
Rating ("GVWR"). The Gross Axle Weight Rat­
ing ("GAWR") is the maximum load that can
be applied at each of the veh icle 's two axles.
The Gross Vehicle Weight Rating and the
Gross Axle Weight Rat ing a re listed on the
safety compliance st ic k er labe l located on the
d river's side B-p illar. T he tire pressure label on
your Audi lists the maximum combined
weight of a ll of the occupants and luggage or
othe r cargo that the vehicle can carry. For the
locat ion of the tire pressure label¢
fig. 208.
A WARNING
Overloading a vehicle can cause loss of ve­
hicle control, a cras h or other acc ident, se­
r ious personal in ju ry, and even death.
- Carry ing more weight than your vehicle
was designed to carry will prevent the
vehicle from handling p roperly and in­
cr ease the risk of a loss of veh icle con­
tro l.
- T he brakes on a veh icle that has been
overloaded may not be ab le to stop the
vehicle within a sa fe distance.
- Ti res on a vehicle that has been ove rload­
ed can fail suddenly causing loss of con­
tro l and a crash .
- Always make su re that the tota l load be­
ing t ransported -including the we igh t of
a tra ile r hi tc h and the tongue weight of a
loaded t ra iler -does not make the veh i­
cle heavier than the ve hicle's Gross Vehi­
cle Weight Rating.
A WARNING
- Incorrect tire pressures and/or underin­
flation can lead to a serious or fatal acci­dent .
-
'
-Incorrect tire pressures and/or underin­
f lation ca use increased tire wear and can
affect the handling of the vehicle .
- Incorrect tire pressures and/or underin­
flation can a lso lead to sudden t ire fail­
ure, including a blowout and sudden de­
flation, caus ing loss of veh icle control.
Checking tire pressure
The correct tire pressure for the tires original­
ly ins talled on your vehicle is lis ted on the tire
pressure label located on driver's side 8-pil­
lar .
The recommended tire pressures are on the
tire pressure label and in the table
¢
page 252, Cold tire inflation pressure. This
means that the pressure m ust be checked and
adjusted when the t ire has not been dr iven fo r
more than a couple of miles (kilomete rs) a t
low speeds d uring the prev ious t hree ho urs.
Air in the tires expands when the tire heats up
as a result of interna l friction as it flexes in
u se . T he tire pressure is higher when the tire
has warmed up than when it is "cold."
It is the inflation pressure in a "co ld" t ire that
counts . Therefore, you should never let air out
of a warm tire to match "Cold tire inflation
pressure" recommendat ions ¢
page 252 . The
t ires wou ld then be underinflated and could
fail suddenly .
The tire pressure label on your Audi lists the recommended co ld tire inflation pressures at
maximum capacity for the new, orig inal
equipment tires that were on your vehicle at
the time it was ma nufactu red . Fo r the loca ­
t ion of the label¢
page 252, fig . 208 .
Most tires lose air naturally over t ime . They
can a lso lose some air if you drive over a pot­
hole or hit a curb while park ing . It is usually
not possible to see whether the rad ial tires
u sed today are unde rinflated just by loo kin g
at them.
T herefo re, be sure to check t ire p ressures at
least once a month and always befo re going
o n a long trip. Ma ke su re to ta ke the numbe r
II>-

A WARNING ,~
Overloading a vehicle can cause loss of ve­
hicle control, a crash or other accident, se ­
rious persona l injury, and even death .
- Carrying more weight than your vehicle
was designed to carry will prevent the
vehicle from handling properly and in­ crease the risk of the loss of vehicle con­
trol.
- The brakes on a vehicle that has been
overloaded may not be able to stop the
vehicle within a safe distance.
- Tires on a vehicle that has been overload­
ed can fail suddenly, including a blowout
and sudden deflation, causing loss of
control and a crash.
- Always make sure that the total load be­
ing transported -including the weight of
a trailer hitch and the tongue weight of a
loaded trailer -does not make the vehi­
cle heavier than the vehicle's Gross Vehi­
cle Weight Rating.
Determining correct load limit
Use the example below to cal­
culate the total weight of the
passengers and luggage or oth­
er things that you plan to trans­
port so that you can make sure
that your vehicle will not be
overloaded.
Steps for Determining Correct Load Limit
1. Locate the statement "THE
COMBINED WEIGHT OF OC­
CUPANTS AND CARGO
SHOULD NEVER EXCEED XXX
KG OR XXX LBS" on your ve­
hicle's placard (tire inflation
Tires and wheels 257
pressure label) ¢ page 252,
fig. 208.
2. Determine the combined
weight of the driver and pas­
sengers that will be riding in
your vehicle.
3. Subtract the combined weight of the driver and pas­
sengers from
"XXX" kilo­
grams or
"XXX" pounds
shown on the sticker
¢ page 252, fig. 208.
4. The resulting figure equals
the available amount of car­
go and luggage load capaci­
ty. For example, if the
"XXX"
amount equals 1400 lbs.
and there will be five 150
lbs. passengers in your vehi­
cle, the amount of available
cargo and luggage load ca­
pacity is 650 lbs. (1400-7 50
(5
X 150) = 650 lbs.)
5. Determine the combined weight of luggage and cargo
being loaded on the vehicle.
That weight may not safely
exceed the available cargo
and luggage load capacity
calculated in Step 4.
6. If your vehicle will be towing
a trailer, load from your trail­
er will be transferred to your
i,,,.
•
•

26 2 T ire s and wheel s
Driving with different tires reduces vehi­
cle handling and can lead to a loss of
co ntrol.
- I f the spare tire is not the same as the
t ires that are mounted on the veh icle -
for example with winter tires - only use
the spare tire for a short period of time
and dr ive with extra care . Refit the nor­
ma l road wheel as soon as safely possi­
ble.
- Never drive faste r than the maximum
speed for which the tires on your veh icle
are rated because ti res that a re driven
faster than their rated speed can fail
sudden ly .
- Overloading t ires cause heat build- up,
sudden tire failure, including a blowout
and sudden deflation and loss of control.
- T emperature grades app ly to tires that
are properly inflated and not over o r un­
derinflated .
- For technical reasons it is not a lways
possible to use wheels from other
vehicles -in some cases not even wheels
from the same vehicle model.
- If you insta ll wheel trim discs on the ve­
hicle whee ls, make sure that the air f low
to the brakes is not blocked. Reduced air­
flow to the brakes can them to overheat, increasing stopping distances and caus­
ing a collision .
- Run flat t ires may on ly be used on
vehicles that were equ ipped w ith them
at the facto ry . The vehicle must have a
chassis des igned for run f lat t ires . Incor­
rect use of run flat tires can lead to vehi­
cle damage or acc idents. Check with an
au thorized Aud i dealer or ti re specia list
to see if your vehicle can be equipped
with run f lat tires. If run flat tires are
used, they must be installed on all four
wheels . Mix ing tire types is not permit­
ted .
(D Note
-For technica l reasons, it is not generally
possib le to use the whee l rims from oth- er veh
icles. This can hold true for wheels
of the same vehicle type.
- If the spare tire is d iffe rent from the
tires that yo u have mounted on your ve­
hicle (for example winter tires o r wide
profi le tires), then use the spare tire for a
short period of time only and drive w ith
extra care. Replace the flat tire w ith the
tire matching the others on your vehicle as soon as possible .
- Never drive without the valve stem cap .
T he valves could get damaged .
® For the sake of the environment
Dispose of o ld tires in accordance with the
l ocal requirements.
Uniform tire quality grading
- Tread wear
- Traction AA A B C
- Temperature ABC
Quality grades can be found where applicab le
on the t ire s ide wall between tread shou lder
and maximum section width
c> page 259,
fig. 212 .
For example : Tread wear 200, Traction AA,
Temperature A.
All passenger ca r tires must conform to Feder­
al Safety Requirements in addition to these
grades.
Tread wear
T he tread wear grade is a comparative rating
based on the wear rate of the t ire when tested
u nder contro lled conditions o n a specified
government test course .
For example, a tire graded 1S0 would wear
one and o ne ha lf ( 11/2) times as well on the
gover nment course as a t ire g raded 100 .
The relative performance of tires depends upon the actual conditions of their use, how­
ever, and may depa rt s ignificantly from the
norm due to va ria tions in d riving hab its, se rv­
ice practices and differences in road character-
istics and climate.
ll-

298 Index
Operation . . . . . . . . . . . . . . . . . . . . . . . . . 80
Setup ..... ................ ..... .. 82
Automatic climate control system
synchron izing .......... .. .. .. .. .. .. 81
Automatic transmission . .. .. .. .. .. .. . 116
Automatic transmission (tiptronic) Emergency mode . . . . . . . . . . . . . . . . . . 120
Kick -down . . . . . . . . . . . . . . . . . . . . . . . . 119
Manual shifting .......... .. .. .. .. . 119
Parking lock emergency release . .. .. . 121
Selector lever positions . . . . . . . . . . . . . 116
Automatic wipers .................. .. S3
Auto Safety Hotline . . . . . . . . . . . . . . . . . 143
Average consumption ........... .. .. .. 25
Average speed . . . . . . . . . . . . . . . . . . . . . . . 25
Avoid damaging the vehicle ...... .. .. . 209
B
Battery . . . . . . . . . . . . . . . . . . . . . . . . . . . 243
Charging . .. ................ ... .. . 245
I mportant warnings .......... .. .. . 243
L ocat ion . . . . . . . . . . . . . . . . . . . . . . . . . 243
low ... .. .. .. . .......... .. .. .. .. . 204
Replacing the battery . . . . . . . . . . . . . . 246
State of charge ............ ... .... . 204
Winter operation .......... ... .... . 243
Working on the battery .... .. .. .. .. . 243
Before driving ........... .. .. .. .. .. . 135
Blended gasoline . ...... ... .... .. .. . 222
Blower (automatic climate control) . ... .. 81
Booster seats .............. ... .. ... 185
Brake fluid Changing the brake fluid ... .. .. .. .. . 242
Check ing the brake fluid level ... .. .. . 242
What is the correct brake fluid level? .. 242
What should I do if the brake fluid warn-
ing light comes on? ..... .. .. .. .. .. . 242
Brake system Anti-lock braking system ... .. .. .. .. . . 19
Brake assist system ......... .. .. ... 199
Brake booster . .. ...... .... ... .. .. . 203
Brake fluid .............. .... ..... 242
Brake fluid spec ificat ions for refill and re­
p la cement . . . . . . . . . . . . . . . . . . . . . . . 242
Brake light defective ....... ... .... . . 22
Brake pads ............... ... .... . 207
Electromechanica l parking brake .. .. . . 86 Fluid
reservoir ... ................ . 242
How does moisture or road salt affect the
brakes? .......................... 201
Warning/indicator lights ........ .... . 14
Worn brake pads symbol . . . . . . . . . . . . . 20
braking guard Messages ..... .. ............. .... 101
Braking guard . .. .. ... .......... .. .. . 94
Settings .. .... ............... .... 101
Break-in period .. .. ... .......... .. .. 207
Brake pads .. .. .. .......... ... .. .. 207
Tires ...... ... .. .. ........ ... .. .. 207
Bul bs .. .... .... ................... 282
C
California Proposition 65 Warning ..... 232
Battery specific . . . . . . . . . . . . . . . . . . . 24S
Capacities .. .. .. . .............. .. .. 290
Engine oil ..... .. ... .......... .. .. 234
Carbon parts Cleaning . . . . . . . . . . . . . . . . . . . . 218,219
Car carrier Transporting your vehicle ....... .... 287
Care ... .... .... ............... .... 216
Cargo area
refer to Luggage compartment . .. .. .. 141
Catalytic converter . ................. 208
Center armrest
Cockpit ........................... 61
Rear ............................. 68
Central locking .. .. ... ........... ... . 33
Emergency locking .. ........... .... . 37
Certification .. .. .. ............. .. .. 29S
Changing a wheel .. ............. .... 272
Chang ing engine oil ....... ...... .. .. 238
Checking Engine coolant level . ........... .. .. 240
Tire pressure .................... .. 254
Child restraints Danger of using child restraints in the
front seat . ................... .... 15S
Where can I get additional information
about child restraints and their use? .. 196
Child restraint system anchors ..... ... 190